In the past, roofing shingles have had to satisfy two main functions when applied to a roof deck. The first function is to provide a durable, weatherproof covering for the roof deck. Roof shingles, whatever their form, are intended to provide a means of sheltering the structure below the shingles from precipitation and the deleterious effects of sun and wind. Roof shingles installed on the roof deck must perform these protecting functions for a reasonable period of time.
The second function is to present an aesthetically pleasing architectural feature which enhances the overall appeal of the structure to which the shingles have been applied. This aesthetic function has been satisfied by providing asphalt shingles with various butt edge contours and surface treatments which operate to simulate more traditional, and in most cases more expensive, forms of roof coverings, such as thatch, wooden shakes, slates, and even tiles of various forms.
In order to satisfy the aesthetic function, shingles have been manufactured using a laminated design to increase the appearance of depth in the shingle. A laminated shingle design typically includes an overlay member laminated to an underlay member. The overlay member may have tabs of varying lengths and may be finished with granules of varying colors. Similarly, the underlay may have tabs generally corresponding to the overlay tabs. Portions of the underlay may have granules of varying color for the additional appearance of depth.
It would be advantageous to produce a shingle having the appearance of depth, more efficiently.